Pediatric renal transplantation and the dysfunctional bladder

A systematic review of kidney transplantation outcomes in patients with end-stage renal disease due to childhood lower urinary tract malformations

PURPOSE

Patients with lower urinary tract malformations (LUTM) were suspended from kidney transplantation (KT) programs in the past due to various concerns. Consequently, only a limited number of studies have explored this topic at hand. In this study, our objective was to perform a systematic review (SR) to evaluate the current evidence regarding KT outcomes as well as patient survival (PS), postoperative complications and urinary tract infections (UTI) in individuals with childhood LUTM.

METHODS

The search encompassed databases of Web of Science, Medline (via PubMed), and Embase (via Scopus) to identify all studies reporting outcomes on KT for patients with LUTM. The research included articles published in English from January 1995 till September 2023.

RESULTS

Of the 2634 yielded articles, 15 met the inclusion criteria, enrolling a total of 284,866 KT patients. There was significantly better 5-year graft survival (GS) in recipients with LUTM compared to the control group (RR, 1.04; 95% CI 1.02-1.06); while GS at 1-year and 10-year, and PS at 1-year, 5-year and 10-year were similar between groups. On the other hand, the postoperative UTI rate was significantly higher in the LUTM group (RR: 4.46; 95% CI 1.89-10.51). However, data on serum creatinine and estimated glomerular filtration rate on follow-up were insufficient.

CONCLUSION

GS and PS rates appear to be similar in patients with childhood LUTM and those with normal lower urinary tract functions. Despite a higher postoperative UTI rate within this patient group, it appears that this has no effect on GS rates.

Surgical considerations in paediatric kidney transplantation: an update

Background

Kidney transplantation has established itself as the most appropriate mode of renal replacement therapy for the majority with end-stage kidney disease. Although at present this is applicable for children as well as adults, a few decades back kidney transplantation was not considered a first-line option in children. This was due to inferior outcomes following transplantation in this age group compared to that of adults. These poor results were attributed to challenges in paediatric transplantation such as the shortage of suitable donors, technical difficulties in performing a sound vascular anastomosis and the adverse effects of immunosuppressive medication on growth and development. However, current patient and graft-centred outcomes after paediatric transplantation equal or surpass that of adults. The advances in evaluation and management of specific surgical concerns in children who undergo transplantation, such as pre-transplant native nephrectomy, correction of congenital anomalies of the urinary tract, placement of an adult-sized kidney in a small child and minimizing the risk of allograft thrombosis, have contributed immensely for these remarkable outcomes.

Conclusions

In this review, we aim to discuss surgical factors that can be considered unique for children undergoing kidney transplantation. We believe that an updated knowledge on these issues will be invaluable for transplant clinicians, who are dealing with paediatric kidney transplantation.

Graft and Patient Survival Rates in Kidney Transplantation, and Their Associated Factors: A Systematic Review and Meta-Analysis

Background:

End-Stage Renal Disease (ESRD) is an irreversible impairment of kidney function that leads to permanently dependent on alternative therapies such as hemodialysis, peritoneal dialysis, and renal transplantation. This study aimed to systematically investigate the survival rate of patients with renal transplantation, graft, and its related factors in Iran.

Methods:

This systematic review and meta-analysis drew on articles indexed in six international and one internal databases (Medline/PubMed, ProQuest, Scopus, Embase, SID, and Web of knowledge) until Nov 2020. The reporting of the present study was performed in terms of PRISMA statement. All analyzes were performed using the STATA software.

Results:

Overall, 367 titles from 6 databases were evaluated of which 86 articles met the inclusion criteria. According to the random model, the graft survival rate at one, three, five, and 10 years were 92.48%, 85.08%, 79.96% and 68.15% respectively. Additionally, the patient survival rates at one, three, five, and 10 years were 91.27%, 86.46%, 81.17% and 78.15% respectively. There was a significant relationship between the age recipient and three-year graft survival rate (P=0.021). Additionally, there was an inverse and significant relationship between the donor age and 10-year patient survival rate (P=0.011).

Conclusion:

The patient and graft survival in transplanted kidney patients is comparable with most developed countries.

Lower urinary tract dysfunction in pediatrics progress to kidney disease in adolescents: Toward precision medicine in treatment

Newborn infants who had neurogenic bladder dysfunction (NBD) have a normal upper urinary tract at birth. Most of them will develop deterioration of renal function and chronic kidney disease if they do not receive proper management. Children with NBD can develop renal damage at adolescence or earlier, which is due to high detrusor pressures resulted from poor compliance of the bladder, detrusor overactivity against a closed sphincter or detrusor sphincter dyssynergia. To preserve renal function and prevent deterioration of the kidneys, NBD must be treated immediately after being diagnosed. Over the last few years there was great progress in the treatment of children with the NBD. We searched PubMed and the Cochrane Library for peer-reviewed articles published in any language up to March 10, 2021, using the search term “neurogenic bladder children.” Our search excluded diagnosis, pathophysiology, surgical treatment of spinal cord injury and spina bifida. The research identified the effectiveness of treatment regimens targeting prevention of chronic kidney disease and the indications of kidney transplantation. The results of the research showed that NBD in children should be diagnosed early in life, and the child should receive the proper management. The literature search concluded that the management of NBD in children would be personalized for every case and could be changed according to response to treatment, side effects, child compliance, availability of treatment modality and costs of treatment. The objectives of the study are to present the different options of management of NBD in children and the selection of the proper method in a personalized manner.

Long-Term Renal Transplant Outcome in Patients With Posterior Urethral Valves. Prognostic Factors Related to Bladder Dysfunction Management

Introduction: To obtain a successful renal transplant (RT) outcome in patients with posterior urethral valves (PUV), it is necessary to accomplish an adequate bladder dysfunction treatment. Our aim was to determine prognostic factors related to bladder dysfunction management in long-term RT outcome in patients with PUV. Methods: A retrospective review of patients with PUV who received a first RT after 1985 in our institution with at least 5 years of follow-up was performed. Variables analyzed included prenatal diagnosis, age of diagnosis, initial presentation and management, bladder dysfunction treatment, other surgical treatments, pre-transplant dialysis, age of transplantation, type of donor, immunosuppression regimen, vascular and urological complications, rejections episodes, and graft survival. Results: Fifty-one patients were included in the analysis. Prenatal diagnosis was done in 37.3%. Median age of diagnosis was 0.30 (0-88) months. Initial presentation was vesicoureteral reflux (VUR) in 78% and obstructive ureterohydronefrosis in 35.3%. Initial management was valve ablation (29.4%), pyelo-ureterostomy (64.7%), and vesicostomy (5.9%). In 33.3%, a type of bladder dysfunction treatment was performed: 21.6% bladder augmentation (BA), 15.7% Mitrofanoff procedure, 17.6% anticholinergic drugs, and 27.5% clean intermittent catheterization (CIC). Pre-transplant dialysis was received by 66.7%. Transplantation was performed at 6.28 ± 5.12 years, 62.7% were cadaveric and 37.3% living-donor grafts. Acute rejection episodes were found in 23.6%. Urological complications included recurrent urinary tract infections (UTIs) (31.4%); native kidneys VUR (31.4%); graft VUR (45.1%); and ureteral obstruction (2%). Vascular complications occurred in 3.9%. Mean graft survival was 11.1 ± 6.9 years. Analyzing the prognostic factor that influenced graft survival, patients with had CIC or a Mitrofanoff procedure had a significant better long-term graft survival after 10 years of follow-up (p < 0.05), despite of the existence of more recurrent UTIs in them. A better graft survival was also found in living-donor transplants (p < 0.05). No significant differences were observed in long-term graft survival regarding native kidneys or graft VUR, BA, immunosuppression regimen, or post-transplant UTIs. Conclusion: Optimal bladder dysfunction treatment, including CIC with or without a Mitrofanoff procedure, might result in better long-term graft survival in patients with PUV. These procedures were not related to a worse RT outcome in spite of being associated with more frequent UTIs.

Prune belly syndrome: current perspectives

Prune belly syndrome (PBS) is a rare but morbid congenital disease, classically defined by a triad of cardinal features that includes cryptorchidism, urinary tract dilation and laxity of the abdominal wall musculature. Children often require numerous surgical interventions including bilateral orchidopexy as well as individually tailored urinary tract and abdominal wall reconstruction. Along with the classic features, patients with PBS often experience gastrointestinal, orthopedic, and cardiopulmonary comorbidities.

Infectious disease risks in pediatric renal transplantation

Renal transplantation is a vital treatment option in children with ESRD with more than 10,000 pediatric kidney transplants and survival rates of greater than 80% at 10 years post-transplant in the USA alone. Despite these advances, infection remains a significant cause of morbidity in pediatric recipients. Screening potential organ donors and recipients is imperative to identify and mitigate infectious risks in the transplant patient. Despite the unique risks of each patient, the timing of many infections post-transplant is predictable. In early post-transplant infections (within 30 days), bacterial and fungal pathogens predominate with donor-derived events and nosocomial infections. In the intermediate period (31-180 days after transplant), latent infections from donor organs, such as EBV and CMV, develop. Late infections occurring > 180 days after the transplant can be due to latent pathogens or community-acquired organisms. Approaching an infectious evaluation in a pediatric kidney recipient requires finesse to diagnose and treat this vulnerable population in a timely manner. The following article highlights the most relevant and common infections including clinical manifestations, risk factors, diagnostic techniques, and treatment options.

Kidney transplantation in an adult patient with VACTERL association

The vertebral, anal, cardiac, tracheoesophageal, renal, and limb birth defects (VACTERL) association is a rare, non-random constellation of congenital abnormalities among which urinary tract anomalies can be included. In the presence of these anomalies, patients are suspected to have a higher rate of renal failure than average. We report a case of a 22-year-old woman with VACTERL association and consequent end stage renal failure. A live-related kidney transplant was carried out successfully and the postoperative course was uncomplicated. The patient had immediate graft function. Risk factors that may complicate kidney transplant surgery in this patient population as well as considerations relevant to peritransplant management are discussed.

Timing and outcome of renal replacement therapy in patients with congenital malformations of the kidney and urinary tract

BACKGROUND AND OBJECTIVES

Congenital anomalies of the kidney and urinary tract (CAKUT) are the leading cause of ESRD in children, but the proportion of patients with individual CAKUT entities progressing to ESRD during adulthood and their long-term clinical outcomes are unknown. This study assessed the age at onset of renal replacement therapy (RRT) and patient and renal graft survival in patients with CAKUT across the entire age range.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Patients with CAKUT were compared with age-matched patients who were undergoing RRT for other renal disorders on the basis of data from the European Renal Association-European Dialysis and Transplant Association Registry. Competing risk and Cox regression analyses were conducted.

RESULTS

Of 212,930 patients commencing RRT from 1990 to 2009, 4765 (2.2%) had renal diagnoses consistent with CAKUT. The proportion of incident RRT patients with CAKUT decreased from infancy to childhood and then increased until age 15-19 years, followed by a gradual decline throughout adulthood. Median age at RRT start was 31 years in the CAKUT cohort and 61 years in the non-CAKUT cohort (P<0.001). RRT was started earlier (median, 16 years) in patients with isolated renal dysplasia than in those with renal hypoplasia and associated urinary tract disorders (median, 29.5-39.5 years). Patients with CAKUT survived longer than age- and sex-matched non-CAKUT controls because of lower cardiovascular mortality (10-year survival rate, 76.4% versus 70.7%; P<0.001).

CONCLUSIONS

CAKUT leads to ESRD more often at adult than pediatric age. Treatment outcomes differ from those of acquired kidney diseases and vary within CAKUT subcategories.

Dysfunctional voiding: A review of the terminology, presentation, evaluation and management in children and adults

Dysfunctional voiding (DV) is a voiding disorder characterized by dyssynergic striated sphincteric activity in the absence of a proven neurological etiology. It can present at any age with a spectrum of storage and voiding symptoms that may resemble florid neurogenic bladder. There is a striking lack of clarity regarding what this entity represents, the diagnostic methodology and treatment. The limitations of existing guideline documents are analyzed. Specifically, use of the term "habitual", the assumption that bladder changes are secondary to the outlet, the emphasis on "staccato" voiding and the implication of striated urethral sphincter are discussed. Literature shows that DV may also present with continuous slow flow or normal flow. Dyssynergia may be at the level of the striated urethral sphincter, the pelvic floor or both, better termed "striated urethral sphincter-pelvic floor complex" (SUS-PFC).A diagnostic algorithm is provided so that patients are evaluated on merit rather than on the basis of different philosophies of individual centers. High-risk markers such as hydronephrosis, vesicoureteral reflux, renal failure or marked voiding difficulty should prompt a formal urodynamics evaluation and imaging for neurological etiology. Patients with predominantly storage symptoms with incidental staccato voiding can be managed initially, on the basis of non-invasive evaluation. Conservative urotherapy including biofeedback is appropriate initial management for patients without high risk factors. Treatment and evaluation should be escalated based on response. Patients with severe DV will need treatment similar to neurogenic bladder including clean intermittent catheterization and measures to control storage pressures.

Urinary tract infections in children after renal transplantation

Urinary tract infections (UTI) after pediatric kidney transplantation (KTX) are an important clinical problem and occur in 15-33% of patients. Febrile UTI, whether occurring in the transplanted kidney or the native kidney, should be differentiated from afebrile UTI. The latter may cause significant morbidity and is usually associated with acute graft dysfunction. Risk factors for (febrile) UTI include anatomical, functional, and demographic factors as well as baseline immunosuppression and foreign material, such as catheters and stents. Meticulous surveillance, diagnosis, and treatment of UTI is important to minimize acute morbidity and compromise of long-term graft function. In febrile UTI, parenteral antibiotics are usually indicated, although controlled data are not available. As most data concerning UTI have been accumulated retrospectively, future prospective studies have to be performed to clarify pathogenetic mechanisms and risk factors, improve prophylaxis and treatment, and ultimately optimize long-term renal graft survival.

Chronic kidney disease in the VACTERL association: clinical course and outcome

Approximately 60% of VACTERL (vertebral defects, anal atresia, cardiac defects, tracheoesophageal fistula with atresia, renal defects/radial limb dysplasia) patients have renal anomalies that can be associated with chronic kidney disease (CKD). With improved medical care, a large proportion of these patients survive into adulthood. Longitudinal follow-up data regarding the management of kidney disease in these children is lacking. Twelve VACTERL patients with CKD stage 2-5 and 12 age-matched controls with similar urologic anomalies and CKD [mean follow-up period 15.0 +/- 1.4 (SE) and 11.9 +/- 2.1 years, respectively] were identified in a single center. Eight VACTERL patients progressed to end-stage renal disease (ESRD) compared to four controls (66.7 vs. 33.3%, respectively). Six VACTERL patients were dialyzed pre-transplant. Of the four patients on peritoneal dialysis (PD), three had to be switched to hemodialysis due to complications, whereas two of the three controls on PD did not experience significant problems. Seven VACTERL patients underwent renal transplantation compared to four controls. Mean creatinine clearance 2 years post-transplant was 65.8 +/- 6.3 in VACTERL patients vs. 87.8 +/- 7.1 ml/min per 1.73 m(2) in controls (p = 0.03). VACTERL patients had a significantly lower mean height standard deviation score than the controls (-2.34 +/- 0.41 vs. -1.27 +/- 0.24, respectively; p < 0.05). Based on these results, VACTERL patients with CKD develop ESRD more frequently, experience more complications with dialysis, may have a poorer transplant outcome, and have more severe growth failure than controls.

Comparison of chronic peritoneal dialysis outcomes in children with and without spina bifida

This study was designed to compare chronic peritoneal dialysis (CPD) long-term outcomes (patient and technique survival, incidence of peritonitis, and overall average death outcomes) between seven patients with lumbar spina bifida (SB) and 20 controls without SB. Both groups were matched for potentially outcome-confounding factors: gender, and socioeconomic status (SES). SES was established using modified Graffar's method. No significant differences were found in CPD outcomes. The incidence of peritonitis was one episode per 17.6 and 10.3 months in SB patients and controls, respectively (p = 0.5). Overall patient survival at 5 years was 86% and 73% in SB patients and controls, respectively (p = 0.55). Overall average death rate between SB and control patients was 47.6/1,000 and 79.4/1,000 patient years, respectively (p = 0.63). Overall technique survival at 5 years was 83% and 73% in SB patients and controls, respectively (p = 0.84). There were no cases of retrograde brain ventricular infection secondary to PD-related peritonitis. We conclude that SB is not a risk factor for CPD, and therefore, it is an effective renal replacement alternative in children with SB.

Renal transplantation in children with posterior urethral valves

The objective of this study was to analyze whether renal transplantation (RT) in children with posterior urethral valves (PUV) constitutes a special group with respect to groups with different etiologies of end-stage renal disease (ESRD). Between 1979 and 2004, 22 RT were performed in 19 children with PUV. The median age at RT was 10 years (range: 1.3-17). Immunosuppression was provided by triple therapy and polyclonal/monoclonal antibodies. This group was compared with the two control groups: (1) glomerulopathy (n=62) and (2) pyelonephritis/dysplasia (n=42) without lower urinary tract disease, transplanted in the same period. Ten graft losses occurred in 22 transplants: thrombosis (2), acute rejection (3), chronic graft nephropathy (2), and death of patients (3) with a functioning graft in the 1st postoperative month. We did not find significant differences versus the control group in renal function or probability of graft or patient survival at 1, 5, and 10 years. We observed a greater risk of urological complication in patients with PUV. RT with PUV constitutes a special group due to the compulsory young age and the need for careful and complex medicosurgical management; nevertheless, the results achieved were similar to those obtained in our general RT population.